The present invention relates to a drying apparatus with a dryer for a textile web, having a drying chamber with at least one air-permeable drum positioned rotating therein, wherein the textile web is guided over a partial section of the drum circumference, wherein heated drying air can flow through the textile web, and wherein a device for introducing heat is provided for heating up the drying air.
The DE 10 2012 109 878 B4 discloses a dryer for a textile web, comprising a drying chamber in which several air-permeable drums are arranged rotating. Via the suction side, a ventilator pulls moist drying air from the inside of the drum, wherein each drum is assigned a separate ventilator. The suction draft formed with the drying air in front of the ventilator, flows through the ventilator and travels to the heating and ventilation chamber. An intermediate chamber is positioned between an end face of the drums and the heating and ventilation chamber and forms a closed chamber which, however, is in contact with the suction draft. The moist drying air consequently flows from the inside of the drum into the intermediate chamber, and the ventilator finally suctions in the drying air via its suction side and releases it to the heating and ventilation chamber. Fresh air is added to the drying air in the intermediate chamber, and a portion of the moist drying air is discharged as exhaust air from the intermediate chamber. It is proposed that in order to improve the effect, a heat exchanger is used to heat up the suctioned-in fresh air with the aid of the discharged exhaust air, so that the fresh air is pre-heated when it enters the intermediate chamber. The effectiveness of the dryer can thus be increased in that less heating energy must be introduced by the heating elements arranged in the heating and ventilation chamber because of the pre-heating of the fresh air.
The heating elements are be designed such that the heat required for realizing the drying process can be provided completely by the dryer.
Depending on the shape and size as well as moisture content of the textile web, dryers of interest require heating capacities ranging from one to several megawatts. If the heating capacity is made available by gas blower burners, for example, then these must be dimensioned accordingly. In the process, up to 1.5 kWH may be necessary for each kilogram of textile web, so that it is desirable to advantageously modify the device for introducing heat.